Physics Past Paper - The Richmond upon Thames School

The diagram below shows a lift near the bottom of a building. 1. The lift is attached by a cable to a counterweight. An electric motor moves the lift. The lift is moving up. (a) As the lift moves up, how far does the counterweight move down? ✓) one box....

The diagram below shows a lift near the bottom of a building. 1. The lift is attached by a cable to a counterweight. An electric motor moves the lift. The lift is moving up. (a) As the lift moves up, how far does the counterweight move down? ✓) one box. Tick (✓ A shorter distance than the lift. The same distance as the lift. A longer distance than the lift. (1) The Richmond upon Thames School Page 1 of 138 (b) What happens to the gravitational potential energy of the counterweight as it moves down? ✓) one box. Tick (✓ It decreases It stays the same It increases (1) (c) Calculate the change in gravitational potential energy of the lift when it moves up 4.0 m The mass of the lift is 1300 kg gravitational field strength = 9.8 N/kg Use the equation: gravitational potential energy = mass × gravitational field strength × height ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ Change in gravitational potential energy = _______________ J (2) The Richmond upon Thames School Page 2 of 138 (d) Complete the sentences. Choose answers from the box. chemical elastic potential gravitational potential internal kinetic Friction between the brakes and the cable causes the speed of the lift to decrease. As the speed decreases, there is a decrease in the _______________ energy of the lift. As the speed decreases, there is an increase in the _______________ energy of the brakes. (2) (e) The motor transfers different amounts of energy each time people use the lift. Which factors affect the amount of energy transferred by the motor as the lift moves? ✓) two boxes. Tick (✓ The distance moved by the lift The height of the building The length of the steel cable The maximum power of the motor The weight of the people in the lift (2) The Richmond upon Thames School Page 3 of 138 (f) The weight of the lift and the counterweight stretch the cable by 0.015 m The cable acts like a spring with a spring constant of 880 000 N/m Calculate the elastic potential energy of the stretched cable. Use the equation: elastic potential energy = 0.5 × spring constant × (extension)2 ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ Elastic potential energy = _______________ J (2) (g) A lift system using a counterweight is more efficient than a lift system that does not use a counterweight. How does having a more efficient system affect the energy transferred by the motor? ✓) one box. Tick (✓ Less energy is transferred. The same amount of energy is transferred. More energy is transferred. (1) (Total 11 marks) The Richmond upon Thames School Page 4 of 138  A trampoline is made from a sheet of material held in place by stretched springs. 2. The figure below shows a child on a trampoline. (a) Position A shows the child’s maximum height above the trampoline. Position B shows the lowest position reached by the child when landing on the trampoline. Describe the changes to the stores of energy of the: child springs surroundings as the child moves from position A to position B. Child ______________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ Springs ____________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ Surroundings _______________________________________________________ ___________________________________________________________________ ___________________________________________________________________ (4) The Richmond upon Thames School Page 5 of 138 (b) When the child is at position A, each trampoline spring is stretched by 0.056 m The elastic potential energy of each spring is 4.9 J When the child is at position B, the elastic potential energy of each spring increases to 8.1 J Calculate the extension of each spring when the child is at position B. Use the Physics Equations Sheet. ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ Extension = _______________ m (5) The Richmond upon Thames School Page 6 of 138 (c) As the child bounces on the trampoline the child does work. What is the work done by the child equal to? ✓) one box. Tick (✓ The average force applied by the child The maximum force applied by the child The total energy store of the child The total energy transferred by the child (1) (Total 10 marks) The Richmond upon Thames School Page 7 of 138  In a sport called far-leaping, an athlete uses a long pole to cross a river. 3. Figure 1 shows an athlete far-leaping. Figure 1 Figure 2 shows the athlete in different stages of far-leaping. Figure 2 The Richmond upon Thames School Page 8 of 138 (a) Complete the sentence. Choose answers from the box. chemical nuclear kinetic elastic gravitational potential potential Between positions A and B the athlete speeds up. There is an increase in the athlete’s _________________________ energy and a decrease in the athlete’s _________________________ store of energy. (2) (b) Between positions B and C the athlete jumps to the pole and climbs up it. Which statement describes a change in the athlete’s energy between positions B and C? ✓) one box. Tick (✓ Elastic potential energy decreases. Elastic potential energy increases. Gravitational potential energy decreases. Gravitational potential energy increases. (1) The Richmond upon Thames School Page 9 of 138 (c) The pole falls over from position C. The athlete lets go of the pole and lands at position D. The change in height of the athlete between positions C and D is 3.0 m. mass of athlete = 50 kg gravitational field strength = 9.8 N/kg Calculate the change in gravitational potential energy of the athlete between positions C and D. Use the equation: ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ Change in gravitational potential energy = _______________J (2) The Richmond upon Thames School Page 10 of 138 (d) The kinetic energy of the athlete at position D is 1600 J. mass of athlete = 50 kg Calculate the speed of the athlete at position D. Use the equation: Choose the unit from the box. m/s J/kg J/s ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ Speed = __________ Unit __________ (3) Figure 2 is repeated below. Figure 2 The Richmond upon Thames School Page 11 of 138 (e) At positions A and E, the athlete is standing still. Why does the athlete have less energy in position E than in position A? ✓) one box. Tick (✓ Energy has been transferred from the athlete to the air. The air temperature has decreased. The height of the athlete above the water has increased. (1) (f) Athletes have a large power output when they are far-leaping. What is meant by the power of an athlete? ✓) one box. Tick (✓ The rate at which the athlete transfers energy. The size of the maximum force exerted by the athlete. The total energy transferred by the athlete. (1) The Richmond upon Thames School Page 12 of 138  (g) A second athlete crossed the same river by far-leaping. The second athlete had less power than the first athlete when running between position A and position B. Complete the sentences. Choose answers from the box. Each answer may be used once, more than once or not at all. less than the same as more than Two factors that could explain why the second athlete had less power than the first athlete are: 1. The time taken by the second athlete to run between position A and position B was ____________________ the first athlete. 2. The work done by the second athlete was ____________________ the first athlete. (2) (Total 12 marks) The diagram below shows a wood-fired hot tub. 4. The Richmond upon Thames School Page 13 of 138 (a) What type of fuel is wood? ✓) one box. Tick (✓ A non-renewable biofuel A non-renewable fossil fuel A renewable biofuel A renewable fossil fuel (1) (b) Give two environmental effects of using wood as an energy resource. 1. _________________________________________________________________ ___________________________________________________________________ 2. _________________________________________________________________ ___________________________________________________________________ (2) (c) Describe the change to the stores of energy of the wood, pipe and water as the water is heated. Wood _____________________________________________________________ ___________________________________________________________________ Pipe ______________________________________________________________ ___________________________________________________________________ Water _____________________________________________________________ ___________________________________________________________________ (3) The Richmond upon Thames School Page 14 of 138  (d) The temperature of the water reaches 42 °C The temperature then stays constant even though the fire continues to burn. Explain why the temperature of the water stays constant. ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ (2) (Total 8 marks) An eco-house is designed to be environmentally friendly. 5. The diagram below shows a picture of an eco-house. The Richmond upon Thames School Page 15 of 138 (a) The solar panels and a wind turbine are used to generate electricity for the eco-house. Solar and wind are both renewable energy resources. What does renewable energy resource mean? ✓) one box. Tick (✓ It can be replenished as it is used. It is unreliable. It has no fuel costs. It produces no greenhouse gases. (1) (b) Biomass, nuclear and natural gas are three other energy resources. Complete the table to show whether each energy resource is renewable or non-renewable. ✓) one box for each energy resource. Tick (✓ Energy resource Renewable Non-renewable Biomass Nuclear Natural gas (2) The Richmond upon Thames School Page 16 of 138 (c) Moving air makes the wind turbine spin. The wind turbine generates electricity which is used to charge a battery. Complete the sentences. Choose answers from the box. chemical electrical gravitational kinetic When the wind turbine spins faster there is an increase in its _______________ energy. Charging the battery increases the _______________ store of energy of the battery. (2) (d) The roof of the eco-house is covered with soil. Covering the roof with soil decreases the thermal conductivity of the roof. What are the advantages of having a roof with a lower thermal conductivity? ✓) two boxes. Tick (✓ Less energy is needed to heat the house. The rate of energy transfer by conduction is greater. The roof is a better insulator. The roof is less likely to leak. Weather will have a greater effect on the temperature of the house. (2) The Richmond upon Thames School Page 17 of 138 (e) The average power transferred to the solar panels by sunlight is 26 000 W Calculate the average energy transferred to the solar panels in 30 seconds. Use the equation: energy transferred = power × time ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ Average energy transferred to solar panels = _______________ J (2) (f) Write down the equation that links efficiency, total power input and useful power output. ___________________________________________________________________ ___________________________________________________________________ (1) (g) The solar panels on the roof of the eco-house have an efficiency of 0.15 The average power input to the solar panels is 26 000 W Calculate the average useful power output from the solar panels. ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ Average useful power output = _______________ W (3) The Richmond upon Thames School Page 18 of 138  (h) Explain why it is a good idea for the eco-house to have both a wind turbine and solar panels. ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ (2) (Total 15 marks) The graph below shows a distance-time graph for 50 seconds of a bicycle ride. 6. (a) The gradient of the distance-time graph gives the speed of the bicycle. Determine the speed of the bicycle. ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ Speed = _______________ m/s (2) The Richmond upon Thames School Page 19 of 138 (b) Which force acting on the moving bicycle is a non-contact force? ✓) one box. Tick (✓ Air resistance Friction Gravitational force Normal contact force (1) (c) The bicycle travels a distance of 250 m The bicycle exerts a constant horizontal force of 30 N on the ground. Calculate the work done. Use the equation: work done = force × distance Choose the unit from the box. J kg m ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ Work done = ____________ Unit __________ (3) The Richmond upon Thames School Page 20 of 138 (d) The bicycle travels at a constant speed. Complete the sentences. Choose answers from the box. chemical frictional kinetic magnetic tension As the bicycle moves, work is done against _______________ forces. There is no change in the cyclist’s _______________ store of energy. There is a decrease in the cyclist’s _______________ store of energy. (3) (Total 9 marks) The Richmond upon Thames School Page 21 of 138  The diagram shows a gymnast on a piece of gymnastic equipment. 7. The equipment consists of two bars at different heights. (a) The gymnast exerts a downward force on the bar. What is the size of the upward force acting on the gymnast from the bar? ✓) one box. Tick (✓ It is greater than the downward force. It is less than the downward force. It is the same size as the downward force. (1) The Richmond upon Thames School Page 22 of 138 (b) Why is the weight of the gymnast represented by an arrow? ✓) one box. Tick (✓ Weight is a constant. Weight is a scalar. Weight is a unit. Weight is a vector. (1) (c) The diagram above shows the weight of the gymnast acting from a point. What name is given to this point? ✓) one box. Tick (✓ Centre of force Centre of mass Centre of tension Centre of weight (1) The Richmond upon Thames School Page 23 of 138 (d) The gymnast has a mass of 45 kg gravitational field strength = 9.8 N/kg Calculate the weight of the gymnast. Use the equation: weight = mass × gravitational field strength ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ Weight = ____________________ N (2) (e) The gymnast swings from one bar to the other bar several times. Describe how the gravitational potential energy store and the kinetic energy store of the gymnast change as she moves between the bars. ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ (4) The Richmond upon Thames School Page 24 of 138  (f) Falling on the crash mat reduces the average deceleration of the gymnast compared with falling on a hard surface. Explain why reducing the deceleration is important to the gymnast. ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ (2) (Total 11 marks) The photograph shows a toaster. 8. The toaster is connected to the mains supply using a three-core cable. (a) What is the function of the earth wire inside the cable? ✓) one box. Tick (✓ To carry the current from the supply to the toaster To complete the circuit in the toaster To melt if a fault occurs inside the toaster To stop the metal case of the toaster becoming live if a fault occurs (1) The Richmond upon Thames School Page 25 of 138 (b) Complete the sentences. Choose answers from the box. blue brown orange white yellow The insulation around the earth wire is green and ____________________. The insulation around the live wire is ____________________. The insulation around the neutral wire is ____________________. (3) (c) The toaster is switched on for 120 seconds. The power of the toaster is 850 watts. Calculate the energy transferred by the toaster. Use the equation: energy transferred = power × time ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ Energy transferred = ____________________ J (2) (d) Complete the sentences. Choose answers from the box. chemical elastic potential kinetic thermal When bread is lowered into the toaster, a spring is stretched. The stretched spring stores __________________________ energy. After the bread is toasted, the spring makes the toast move upwards. As the speed of the toast increases, the __________________________ energy of the toast increases. (2) The Richmond upon Thames School Page 26 of 138 (e) Write the equation which links gravitational field strength, gravitational potential energy, height and mass. ___________________________________________________________________ ___________________________________________________________________ (1) (f) The toast was moved upwards by the spring. The change in gravitational potential energy of the toast was 0.049 J The mass of the toast was 0.050 kg gravitational field strength = 9.8 N/kg Calculate the change in height of the toast. ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ Change in height = ____________________ m (3) (Total 12 marks) The Richmond upon Thames School Page 27 of 138  A designer made some shoes that have lights in them. 9. Each shoe has a switch which closes when a person puts their foot on the floor. Figure 1 shows the circuit. Figure 1 (a) What is component X? ✓) one box. Tick (✓ Lamp LDR LED (1) (b) Complete the sentence. Choose the answer from the box. greater than less than the same as When the switch was closed, the current in component X was ________________________________ the current in the resistor. (1) The Richmond upon Thames School Page 28 of 138 The designer tested how the number of cells affected the number of steps that could be taken before the lights stopped working. Figure 2 shows the results. Figure 2 (c) Determine how many more steps could be taken when the number of cells was increased from 3 to 5 ___________________________________________________________________ ___________________________________________________________________ Number of steps = ____________________ thousand (2) The Richmond upon Thames School Page 29 of 138 (d) How could the designer check the repeatability of the results? ✓) one box. Tick (✓ Repeat the experiment with a different resistor in the circuit. Repeat the experiment using exactly the same method. Repeat the experiment with different types of shoe. (1) (e) When the potential difference across the resistor was 0.80 V, the current in the resistor was 0.020 A Calculate the power dissipated by the resistor. Use the equation: power = potential difference × current ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ Power = ____________________ W (2) (f) Which other equation can be used to calculate the power dissipated by a resistor? ✓) one box. Tick (✓ Power = (current)2 × resistance Power = current × (resistance)2 (1) The Richmond upon Thames School Page 30 of 138  (g) What happens to the temperature of the resistor when there is a current in it? ___________________________________________________________________ ___________________________________________________________________ (1) (h) There was a current of 0.020 A in the resistor for 180 seconds. Calculate the charge flow through the resistor. Use the equation: charge flow = current × time ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ Charge flow = ____________________ C (2) (Total 11 marks) The diagram below shows a girl skateboarding on a semi-circular ramp. 10. The girl has a mass of 50 kg The Richmond upon Thames School Page 31 of 138 (a) Calculate the gravitational potential energy (g.p.e.) of the girl at the top of the ramp. Use the equation: g.p.e. = mass × gravitational field strength × height gravitational field strength = 9.8 N/kg ___________________________________________________________________ ___________________________________________________________________ g.p.e. = ________________________ J (2) (b) The girl has a speed of 7 m/s at the bottom of the ramp. Calculate the kinetic energy of the girl at the bottom of the ramp. Use the equation: kinetic energy = 0.5 × mass × (speed)2 ___________________________________________________________________ ___________________________________________________________________ Kinetic energy = ________________________ J (2) (c) Not all of the g.p.e. has been transferred to kinetic energy. Which two statements explain why? Tick two boxes. Some energy is wasted. The mass of the girl is too low. The ramp is not high enough. The g.p.e. of the girl is not zero. The speed of the girl is too great. (2) The Richmond upon Thames School Page 32 of 138  (d) Explain how lubricating the wheels of the skateboard can increase the speed of the girl. Use ideas about energy in your explanation. ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ (3) (Total 9 marks) A student uses an electric motor to lift a load. 11. In the motor, the electrical energy is transferred into other types of energy. Some of this energy is useful and the rest of the energy is wasted. (a) (i) Name the useful energy output from the electric motor. ______________________________________________________________ (1) (ii) What eventually happens to the wasted energy? ______________________________________________________________ ______________________________________________________________ (1) The Richmond upon Thames School Page 33 of 138  (b) The graph shows the input energy the motor needs to lift different loads by one metre. What can you conclude from the graph about the relationship between the load lifted and the input energy needed? ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ (2) (c) A shop uses escalators to lift customers to different floor levels. The escalators use electric motors. When the shop is not busy some escalators are turned off. A sign tells the customers that the escalators are turned off to save energy. The Richmond upon Thames School Page 34 of 138 (i) Each escalator has one motor with an average power of 4000 W. The motor is turned on for an average of 8 hours each day, 6 days each week. Electricity costs 15 pence per kilowatt-hour. Calculate the cost of the electricity used in an average week to run one escalator. Show clearly how you work out your answer. ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ ______________________________________________________________ Cost = _______________________ pence (3) (ii) Give one environmental advantage to turning off electrical appliances when they are not being used. ______________________________________________________________ ______________________________________________________________ (1) (Total 8 marks) The Richmond upon Thames School Page 35 of 138  (a) Figure 1 shows the distance-time graph for a car travelling at 15 m/s 12. Figure 1 When the driver is tired, his reaction time increases from 0.50 seconds to 0.82 seconds. Determine the extra distance the car would travel before the driver starts braking. ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ Distance = _______________________ m (2) (b) When the brakes are used, the temperature of the brakes increases. Explain why. Use ideas about energy in your explanation. ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ (2) The Richmond upon Thames School Page 36 of 138 (c) A lorry travels 84 m with a constant acceleration of 2.0 m/s2 to reach a velocity of 19 m/s Calculate the initial velocity of the lorry. Use the Physics Equations Sheet. ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ Initial velocity = _______________________ m/s (3) (d) Figure 2 shows how the thinking distance, braking distance and stopping distance for a car vary with the speed of the car. Figure 2 The Richmond upon Thames School Page 37 of 138  Describe the relationships shown in Figure 2 You should include factors that would affect the gradient of the lines. ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ (6) (Total 13 marks) The photograph below shows a sailing boat crossing an ocean. 13. There is a wind turbine on the boat. The Richmond upon Thames School Page 38 of 138 (a) The wind turbine generates electricity to charge a battery on the boat. Name one other renewable energy resource that could be used on the boat to generate electricity. ___________________________________________________________________ (1) (b) The boat also has a generator that burns a fossil fuel. The battery can be charged by either the wind turbine or the generator. Give two reasons why this is useful. 1 _________________________________________________________________ ___________________________________________________________________ 2 _________________________________________________________________ ___________________________________________________________________ (2) (c) Explain one environmental impact of using fossil fuels to generate electricity. ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ (2) The Richmond upon Thames School Page 39 of 138 (d) The kinetic energy of the boat is 81 kJ. mass of boat = 8000 kg Calculate the speed of the boat. ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ Speed = _______________ m/s (4) (e) As the boat passes over a wave, the gravitational potential energy of the boat increases by 19 600 J. mass of boat = 8000 kg gravitational field strength = 9.8 N/kg Calculate the change in height of the centre of mass of the boat as it passes over the wave. ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ Change in height = _______________ m (3) (Total 12 marks) The Richmond upon Thames School Page 40 of 138  Kangaroos are large animals that travel by jumping. 14. The photograph below shows a kangaroo. Each leg of a kangaroo has a tendon connected to a muscle. Each tendon can be modelled as a spring. When a jumping kangaroo lands on the ground, the tendons stretch. (a) The diagram below shows a sketch graph of how the maximum tendon length during a jump changes with the speed of the kangaroo. Explain why a kangaroo can jump higher as its speed increases. ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ (3) The Richmond upon Thames School Page 41 of 138 (b) A kangaroo has a maximum gravitational potential energy during one jump of 770 J When the kangaroo lands on the ground 14% of the maximum gravitational potential energy is transferred to elastic potential energy in one tendon. The tendon has an unstretched length of 35.0 cm When the kangaroo lands on the ground the tendon stretches to a length of 42.0 cm Calculate the spring constant of the tendon. ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ Spring constant = _______________ N/m (5) (Total 8 marks) The Richmond upon Thames School Page 42 of 138  An air source heat pump transfers energy from the air outside a building to increase the 15. temperature of the air inside the building. The figure below shows an air source heat pump. The compressor is connected to the mains electricity supply. The pipe in the heat pump contains a substance called coolant. In the evaporator, energy is transferred from the air outside the building to the liquid coolant. The temperature of the coolant increases and it evaporates. (a) Explain what happens to the internal energy of the coolant as its temperature increases. ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ (2) (b) What name is given to the energy needed to change the state of the liquid coolant? ___________________________________________________________________ (1) The Richmond upon Thames School Page 43 of 138 (c) What happens to the mass of the coolant as it evaporates and becomes a vapour? ✓) one box. Tick (✓ Decreases Stays the same Increases (1) (d) The compressor increases the density and temperature of the coolant vapour inside the pipe. Explain why the pressure in the pipe increases. ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ (2) The Richmond upon Thames School Page 44 of 138 (e) The condenser transfers energy from the coolant to the air in the building. When the total energy input to the heat pump system is 1560 kJ the temperature of the air in the building increases from 11.6 °C to 22.1 °C. The efficiency of the heat pump system is 87.5%. The mass of the air inside the building is 125 kg. Calculate the specific heat capacity of the air in the building. Give your answer in standard form. ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ Specific heat capacity (standard form) = _______________ J/kg °C (6) The Richmond upon Thames School Page 45 of 138  (f) The air in the building gains 400 J for every 100 J of energy transferred from the mains electricity supply to the compressor. An advertisement claims that the heat pump system has an efficiency of 400%. Explain why the advertisement is not correct. ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ (3) (Total 15 marks) A scientist had a balloon which was filled with air. 16. (a) Which statement describes how air particles move? ✓) one box. Tick (✓ At random speeds in random directions At random speeds in the same direction At the same speed in random directions At the same speed in the same direction (1) The temperature of the air was 19 °C The scientist dipped the balloon into liquid nitrogen. The temperature of the liquid nitrogen was −196 °C The Richmond upon Thames School Page 46 of 138 (b) Which thermometer could be used to measure the temperature of the liquid nitrogen? ✓) one box. Tick (✓ (1) (c) The scientist wore special insulating gloves when putting the balloon into the liquid nitrogen. Suggest why. ___________________________________________________________________ ___________________________________________________________________ (1) (d) When the balloon was put into liquid nitrogen the temperature of the air in the balloon decreased. Complete the sentences. Choose answers from the box. Each answer may be used once, more than once or not at all. decreased stayed the same increased As the air in the balloon cooled down, the speed of the particles _______________. This is because the kinetic energy of the particles _______________. (2) The Richmond upon Thames School Page 47 of 138 (e) The air in the balloon had a mass of 0.00320 kg The temperature of the air in the balloon decreased by 215 °C The change in thermal energy of the air in the balloon was 860 J Calculate the specific heat capacity of the air in the balloon. Use the Physics Equations Sheet. ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ Specific heat capacity = _______________ J/kg°C (3) (f) The liquid nitrogen boiled. What happens to the temperature of nitrogen as it boils? ✓) one box. Tick (✓ Temperature decreases Temperature increases Temperature stays the same (1) The scientist recorded measurements to calculate the specific latent heat of vaporisation of nitrogen. The Richmond upon Thames School Page 48 of 138 (g) What is meant by vaporisation? ✓) one box. Tick (✓ A change of state from liquid to gas A change of state from solid to gas A change of state from solid to liquid (1) (h) The mass of nitrogen that vaporised was 0.0072 kg 1440 J of energy was transferred to the nitrogen as it vaporised. Calculate the specific latent heat of vaporisation of nitrogen. Use the Physics Equations Sheet. ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ Specific latent heat of vaporisation = _______________ J/kg (3) (Total 13 marks) The Richmond upon Thames School Page 49 of 138  A student made measurements to determine the specific heat capacity of vegetable oil. 17. Figure 1 shows the equipment used. Figure 1 (a) Describe how the student could use the equipment shown in Figure 1 to determine the specific heat capacity of vegetable oil. ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ (6) (b) Give one risk when using the equipment in Figure 1. ___________________________________________________________________ ___________________________________________________________________ (1) The Richmond upon Thames School Page 50 of 138 A different student did not have a joulemeter and calculated the energy transferred by the electric heater. Use the Physics Equations Sheet to answer parts (c) and (d). (c) Write down the equation linking energy transferred (E), power (P) and time (t). ___________________________________________________________________ (1) (d) The electric heater had a power output of 50 watts. Calculate the time taken for the electric element to transfer 4750 joules of energy to the vegetable oil. ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ Time taken = _______________ s (3) The Richmond upon Thames School Page 51 of 138 In a deep fryer, vegetable oil is heated by an electric heating element. Food is then cooked in the hot vegetable oil. The deep fryer contains an electrical component to monitor the temperature of the vegetable oil. Figure 2 shows how the resistance of this electrical component changes with temperature. Figure 2 (e) What electrical component is used to monitor the temperature of the vegetable oil? ___________________________________________________________________ (1) The Richmond upon Thames School Page 52 of 138 (f) The electric heating element in the deep fryer automatically switches off when the vegetable oil reaches a certain temperature. Figure 3 shows how the temperature of the vegetable oil changed after the deep fryer was switched on. Figure 3 Determine the resistance of the electrical component when the electric heating element automatically switched off. Use Figure 2 and Figure 3. ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ Resistance = _______________ Ω (2) The Richmond upon Thames School Page 53 of 138  (g) Some chips were put in the deep fryer. In the deep fryer, water in the chips underwent a physical change and became steam. Why is this a physical change? ✓) one box. Tick (✓ All water can change to steam. No chemicals are involved when water changes to steam. The change from water to steam can be detected visually. The water will recover its original properties if the steam is cooled. (1) (Total 15 marks) Ice cream is made by cooling a mixture of liquid ingredients until they freeze. 18. (a) Which statement describes the motion of the particles in solid ice cream? ✓) one box. Tick (✓ They are stationary. They move freely. They vibrate about fixed positions. (1) The Richmond upon Thames School Page 54 of 138 (b) How do the kinetic energy and the potential energy of the particles change as a liquid is cooled and frozen? ✓) one box. Tick (✓ Kinetic energy Potential energy Decreases Decreases Decreases Does not change Does not change Decreases Does not change Does not change (1) The diagram below shows a bowl used for making ice cream. The walls of the bowl contain a liquid coolant. The bowl is cooled to –20 °C before the mixture is put in the bowl. The bowl causes the mixture to cool down and freeze. The Richmond upon Thames School Page 55 of 138 (c) Explain why the different thermal conductivities of metal and plastic are important in the design of the bowl. Metal ______________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ Plastic _____________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ (4) (d) The liquid coolant has a freezing point below –20 °C Explain one other property that the liquid coolant should have. ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ (2) The Richmond upon Thames School Page 56 of 138 (e) The initial temperature of the mixture was +20 °C. The mixture froze at –1.5 °C. A total of 165 kJ of internal energy was transferred from the mixture to cool and freeze it. specific heat capacity of the mixture = 3500 J/kg °C specific latent heat of fusion of the mixture = 255 000 J/kg Calculate the mass of the mixture. Give your answer to 2 significant figures. ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ Mass (2 significant figures) = _______________ kg (6) (Total 14 marks) The Richmond upon Thames School Page 57 of 138  A scientist cooled the air inside a container. 19. (a) The temperature of the air changed from 20 °C to 0 °C The volume of the container of air stayed the same. Explain how the motion of the air molecules caused the pressure in the container to change as the temperature decreased. ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ (3) (b) The air contained water that froze at 0 °C The change in internal energy of the water as it froze was 0.70 kJ The specific latent heat of fusion of water is 330 kJ/kg Calculate the mass of ice produced. Use the Physics Equations Sheet. ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ Mass of ice = ____________________ kg (3) The Richmond upon Thames School Page 58 of 138 (c) The air also contained oxygen, nitrogen and carbon dioxide. Oxygen boils at −183 °C and freezes at −218 °C Nitrogen boils at −195 °C and freezes at −210 °C Carbon dioxide sublimates at −78 °C The scientist continued to cool the air to a temperature of −190 °C What is the state of each substance at −190 °C? ✓) one box for each row of the table. Tick (✓ Substance Solid Liquid Gas Oxygen Nitrogen Carbon dioxide (2) The Richmond upon Thames School Page 59 of 138  (d) The air also contained a small amount of argon. As the temperature of the air decreased from 20 °C to –190 °C the argon changed from a gas to a liquid to a solid. Explain the changes in the arrangement and movement of the particles of the argon as the temperature of the air decreased. ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ (6) (Total 14 marks) In an experiment, a beam of alpha particles was directed at a thin sheet of gold foil. 20. (a) Most of the alpha particles passed straight through the gold foil. Alpha particles which passed close to the nucleus of a gold atom did not pass straight through. What happened to the alpha particles which passed close to the nucleus of a gold atom? ___________________________________________________________________ ___________________________________________________________________ (1) The Richmond upon Thames School Page 60 of 138 (b) The results suggested that the diameter of the nucleus of a gold atom is of the diameter of the atom. The diameter of a gold atom is 0.18 nm Calculate the diameter of a gold nucleus in nm ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ Diameter = ____________________ nm (2) (c) Further experiments showed that gold nuclei are surrounded by electrons in different energy levels. Figure 1 shows three of the energy levels around the nucleus of a gold atom. Figure 1 The electron in energy level B absorbs electromagnetic radiation. Which energy level will the electron be in after it has absorbed the electromagnetic radiation? ✓) one box. Tick (✓ A B C (1) The Richmond upon Thames School Page 61 of 138 Figure 2 shows how the temperature of a small sample of gold changes as it is heated from a solid to a liquid. Figure 2 (d) What is the melting point of the gold? Melting point = ____________________ °C (1) (e) How many minutes did it take for all of the gold in the sample to change from solid to liquid? Time taken = ____________________ minutes (1) The Richmond upon Thames School Page 62 of 138  (f) What does the gradient of the graph in Figure 2 represent? ✓) one box. Tick (✓ The internal energy of the gold The rate of change of temperature of the gold The specific heat capacity of the gold (1) (Total 7 marks) A student investigated how the mass of water in an electric kettle affected the time taken for the 21. water to reach boiling point. The kettle switched off when the water reached boiling point. Figure 1 shows the kettle. Figure 1 (a) The heating element of the kettle was connected to the mains supply. Explain why the temperature of the heating element increased. ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ (2) The Richmond upon Thames School Page 63 of 138 (b) Give one variable that the student should have controlled. ___________________________________________________________________ ___________________________________________________________________ (1) Figure 2 shows how the mass of water in the kettle affected the time taken for the kettle to switch off. Figure 2 (c) Suggest why the line on Figure 2 does not go through the origin. ___________________________________________________________________ ___________________________________________________________________ (1) (d) Suggest why the results give a non-linear pattern. ___________________________________________________________________ ___________________________________________________________________ (1) The Richmond upon Thames School Page 64 of 138 (e) The power of the kettle was 2.6 kW The kettle took 120 seconds to heat 0.80 kg of water from 18 °C to 100 °C Calculate the specific heat capacity of water using this information. Give your answer to 2 significant figures. ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ Specific heat capacity = ____________________ J/kg °C (6) (Total 11 marks) The Richmond upon Thames School Page 65 of 138  A student investigated the change in temperature when oils of different specific heat capacities 22. were heated. She set up the apparatus shown in the figure below. This is the method used. 1. Put 25 g of oil into a boiling tube. 2. Pour 100 ml of water into a beaker and heat it with a Bunsen burner. 3. When the water is boiling, put the boiling tube into the beaker. 4. When the temperature of the oil reaches 30 °C, heat for a further 30 seconds and record the rise in temperature. 5. Repeat with different oils. 6. Repeat the whole investigation. (a) Name two pieces of apparatus the student used that are not shown in the figure above. 1. _________________________________________________________________ 2. _________________________________________________________________ (2) (b) What are the independent and dependent variables in the student’s investigation? Independent ________________________________________________________ ___________________________________________________________________ Dependent _________________________________________________________ ___________________________________________________________________ (2) The Richmond upon Thames School Page 66 of 138 (c) Give two safety precautions the student should have taken. 1. _________________________________________________________________ ___________________________________________________________________ 2. _________________________________________________________________ ___________________________________________________________________ (2) (d) Suggest one improvement to the student’s method. ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ (2) (e) The table below shows the student’s results. Temperature rise in °C Type of oil 1 2 3 Mean Castor oil 20 19 21 20 Linseed oil 19 18 19 19 Mineral oil 21 21 21 21 Olive oil 17 17 18 Sesame oil 23 23 20 22 Calculate the mean temperature rise for olive oil. Give your answer to two significant figures. ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ Mean temperature rise = __________________ °C (2) The Richmond upon Thames School Page 67 of 138 (f) The mean change in temperature of the castor oil is 20 °C The specific heat capacity of castor oil is 1 800 J / kg °C The mass of oil used is 0.025 kg Calculate the change in thermal energy of the castor oil the student used. Use the correct equation from the Physics Equations Sheet. Select the correct unit from the box. joule newton volt ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ Change in thermal energy = ____________________ Unit = ____________________ (3) (Total 13 marks) The Richmond upon Thames School Page 68 of 138  There are many different energy resources. 23. (a) Which two energy resources are renewable? Tick two boxes. Biofuel Coal Gas Geothermal Nuclear fuel (2) (b) Some non-renewable energy resources are more reliable than others. Which statement correctly describes a reliable resource? Tick one box. It does not burn fuel. It is predictable. It will never run out. It is cheap to use. (1) The Richmond upon Thames School Page 69 of 138 (c) Figure 1 shows a wind farm. Figure 1 The total power output of the wind farm is 19.6 MW All of the wind turbines have the same power output. What is the power output of one wind turbine? Tick one box. 2.7 MW 2.8 MW 2.9 MW 3.2 MW 3.3 MW (1) (d) Give two reasons why people might not like having wind turbines near their homes. 1. _________________________________________________________________ 2. _________________________________________________________________ (2) The Richmond upon Thames School Page 70 of 138 (e) Figure 2 shows the electricity generated by different energy resources in the UK. The total amount of electricity generated was the same in 2014 and in 2015 Figure 2 There are changes in the amounts of different energy resources used between 2014 and 2015 Explain the environmental impacts of the changes. ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ (4) (Total 10 marks) The Richmond upon Thames School Page 71 of 138  Figure 1 shows solid ice on a car’s rear window. 24. Figure 1 © Captive cookies/iStock/Thinkstock The glass window contains an electrical heating element. The Richmond upon Thames School Page 72 of 138 (a) Use the particle model in Figure 2 to describe how the heating element causes the arrangement of the ice particles to change as the ice melts. Figure 2 You should include a description of how the particles are arranged in the solid ice and in the water. ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ (6) The Richmond upon Thames School Page 73 of 138 (b) A car manufacturer tests different heating elements by measuring how long it takes ice to melt. During the test some variables must be controlled. Identify two control variables in the car manufacturer’s test. Tick two boxes. The colour of the car The current in the heating element The mass of ice The size of the car The time taken for the ice to melt (2) (c) Some of the energy supplied by the heater causes the ice to melt without the temperature of the ice increasing. What is the name given to this energy supplied by the heater? Tick one box. Latent heat of freezing Latent heat of fusion Latent heat of vaporisation (1) The Richmond upon Thames School Page 74 of 138  (d) When the heater is supplied with 120 J of energy each second, the internal energy of the ice increases by 45 J each second. Use the following equation to calculate the efficiency of the heater. Efficiency = Give your answer to two decimal places. ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ Efficiency = ____________________ (2) (Total 11 marks) Figure 1 shows a battery operated remote control car. 25. Figure 1 © Brandon Bolin/iStock/Thinkstock The Richmond upon Thames School Page 75 of 138 (a) The car’s battery contains a store of energy. As the car moves, energy from one store is transferred to another store. Describe how different stores of energy change as the car moves. ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ (2) (b) The car has a top speed of 12 m / s and a mass of 800 g. Write down the equation that links kinetic energy, mass and speed. Equation ___________________________________________________________ (1) (c) Calculate the maximum kinetic energy of the car. ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ Maximum kinetic energy = __________________ J (2) (d) Explain why having a more efficient motor increases the top speed of the car. ___________________________________________________________________ _